Nutrient deficiency is a world wide heath problem. Iron deficiency in particular is the most common form of nutritional deficiency in the world, affecting over 3 billion people in the Third World alone. It is associated with a number of diseases and conditions and is blamed for 100,000 maternal deaths during childbirth each year as well as 134,000 deaths among children. It is also co-morbid with a number of parasitic infections and is a key underlying factor in impaired mental development in children.
Iron deficiency anemia is one of the more serious conditions caused by iron deficiency. It is an advanced stage of iron deficiency and occurs when the dietary intake or absorption of iron is insufficient, and hemoglobin, which contains iron, cannot be formed.
Children and pre-menopausal women are the two groups most prone to developing this disease. The principal cause of iron deficiency anemia in premenopausal women is blood lost during menses. Causes in children include malnutrition during pregnancy, malnutrition, premature birth, GI bleeding, and parasitic infection.
The typical form of treatment for iron deficient anemia includes oral or intravenous delivery with various ferrous compounds. However, both of these treatments have a number of limitations. Oral iron preparations in particular have many disadvantages. First and foremost, they cause gastrointestinal side effects including nausea, bloating, constipation, and diarrhea. This leads to discontinuation of iron supplementation in approximately 40-66% of the patients taking such supplements. Furthermore, the absorption of iron is variable and affected by the oral ingestion of other compounds. For example, oral ingestion of food products reduces iron absorption by approximately 50%, which is problematic since many patients take iron with food in order to reduce the gastrointestinal side effects.
Second, many drugs are known to reduce iron absorption. For example, oral ingestion of antacids and other drugs that reduce stomach pH is known to decrease iron absorption. In turn, oral ingestion of iron also reduces the absorption of many drugs, including antibiotics. Additionally, many conditions associated with iron deficiency anemia respond poorly to oral iron supplementation because iron cannot be properly absorbed through the cells of the gastrointestinal system. This is especially true of certain inflammatory conditions of the bowel, such as Crohn's disease. Additionally, diseases associated with functional iron deficiency, such as the anemia of renal failure, are also associated with limited absorption of orally administered iron. This is also true of many other so-called “inflammatory conditions” associated with functional iron deficiency, such as those associated with rheumatoid arthritis and other autoimmune diseases, as well as anemia secondary to cancer or cancer chemotherapy treatment. This is especially true in patients with these conditions who are treated with erythropoietin, who have considerably increased demands for iron.
Intravenous administration also has a number of limitations. These include pain and infection at the injection site, the requirement to be connected to an IV drip for a prolonged period of administration (to reduce the risk of anaphylaxis), and the requirement to mix, store and administer the medication in liquid form using sterile technique. The latter can be particularly problematic in third world countries where adequate refrigeration and sterile needles are not readily available, limiting shelf life and exposing the patient to infection. Also, IV administration can include several risk factors including anaphylaxis, and cardiovascular complications.
Thus, there is a need for improved methods of drug delivery for the treatment of iron deficiency including anemia and other related medical conditions which can extend shelf life and are more easily used in settings lacking refrigeration or sterile medical supplies.